1. Field of the Invention
The present invention relates to a wireless microphone system, a voice receiving apparatus, and a wireless microphone, and more particularly to, a multi-channel wireless microphone system comprising a voice receiving apparatus and a plurality of wireless microphones in a local communication area wherein the voice receiving apparatus is capable of communicating with each of the wireless microphones located in the local communication area without interfering with any one of them to ensure reliable communications.
2. Description of the Related Art
Up until now, there have been proposed a wide variety of wireless microphone systems, each comprising a wireless microphone for collecting a voice and converting the voice thus collected into an audio signal to be transmitted by means of radio wave, and a voice receiving apparatus for receiving the audio signal from the microphone, thereby making it possible for the voice receiving apparatus to receive the audio signal from the wireless microphone and eliminating the need of installing a cable for connecting the wireless microphone and the voice receiving apparatus. The voice receiving apparatus may be connected with, for example, a speaker for amplifying and outputting therethrough the voice thus collected and transmitted by the wireless microphone.
One typical example of the conventional wireless microphone system, hereinlater referred to as “first conventional wireless microphone system”, is exemplified and shown in FIG. 14 as comprising two wireless microphones 901 and 903 each for collecting a voice, converting the voice thus collected into an audio signal, and transmitting the audio signal by means of radio wave on a microphone frequency channel, and two receiving apparatuses 902 and 904 each for receiving the audio signal. The voice receiving apparatus 902 is capable of receiving an audio signal by means of radio wave on a receiving frequency channel from a wireless microphone located within a local communication area L1 while, on the other hand, the voice receiving apparatus 904 is capable of receiving the audio signal by means of radio wave on a receiving frequency channel from a wireless microphone located within a local communication area L2. The wireless microphone 901 is located in the local communication area L1, and the wireless microphone 903 is located in both the local communications areas L1 and L2.
In the first conventional wireless microphone system thus constructed, the microphone frequency channel of the wireless microphone 901 located in the local communication area L1 and the receiving frequency channel of the receiving apparatus 902 may be manually set to a common frequency channel, for example, frequency channel α, so that the wireless microphone 901 could communicate with the receiving apparatus 902. Similarly, the microphone frequency channel of the wireless microphone 903 located in the local communication area L2 and the receiving frequency channel of the receiving apparatus 904 may be manually set to a common frequency channel, for example, frequency channel β, so that the wireless microphone 903 could communicate with the receiving apparatus 904.
The first conventional wireless microphone system, however, encounters a problem that the wireless microphone 903 located in both the local communication areas L1 and L2 cannot communicate with the receiving apparatus 902 while, on the other hand, the wireless microphone 903 can communicate with the receiving apparatus 904 on the frequency channel β unless the microphone frequency channel of the wireless microphone 903 and the receiving frequency channel of the receiving apparatus 902 are manually set to a common frequency channel. The radio wave transmitted by the wireless microphone 903 located in both the local communication areas L1 and L2 and communicating with the receiving apparatus 904 may be recognized by the receiving apparatus 902 as extraneous radio wave and cause a harmful interference with the receiving apparatus 902.
Another conventional wireless microphone system, hereinlater referred to as “second conventional wireless microphone system”, is exemplified and shown in FIG. 15 as comprising a plurality of wireless microphones, for example, wireless microphones 911 to 918 each for collecting a voice, converting the voice thus collected into an audio signal, and transmitting the audio signal by means of radio wave on a microphone frequency channel and a receiving apparatus 900 for receiving the audio signal. The wireless microphones 911 to 918 are located in a local communication area L3, and the voice receiving apparatus 900 is capable of receiving an audio signal by means of radio wave on a receiving frequency channel from a wireless microphone located within the local communication area L3.
In the second conventional wireless microphone system thus constructed, the microphone frequency channel of the wireless microphone 911 and the receiving frequency channel of the receiving apparatus 900 may be manually set to a common frequency channel, for example, frequency channel α1, so that the wireless microphone 911 can communicate with the receiving apparatus 900. Similarly, the microphone frequency channel of the wireless microphone 912 and the receiving frequency channel of the receiving apparatus 900 may be manually set to a common frequency channel, for example, frequency channel α2, so that the wireless microphone 912 can communicate with the receiving apparatus 900. In this manner, the microphone frequency channels of the wireless microphones 911 to 918 and the receiving frequency channels of the receiving apparatus 900 may be manually set to respective common frequency channels, for example, frequency channels α1 to α8 so that the plurality of wireless microphone 911 to 918 can communicate with the receiving apparatus 900.
The second conventional wireless microphone system comprising a receiving apparatus and a plurality of wireless microphone encounters another problem that the microphone frequency channels of the wireless microphones 911 to 918 and the receiving frequency channels of the receiving apparatus 900 are required to be manually set to common frequency channels, i.e., respective frequency channels α1 to α8 so that the plurality of wireless microphone 911 to 918 can communicate with the receiving apparatus 900, thereby making it difficult to manage a plurality of wireless microphones in terms of frequency channels and easily causing harmful interferences with one another. The present invention contemplates resolution of such problems.